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Spanning Tree
If you modify these settings, click
Apply
to save the changes for the current boot session. The
changes take effect immediately but are not retained across a switch reset unless you click
Save Con-
figuration
.
Port Path Cost
Specify the path cost, which is used when establishing the active topology of the network.
Lower path cost ports are chosen as forwarding ports in favor of higher path cost ports.
Specify
Auto
or assign a value from 1 to 200000000, or specify 0 for Auto mode. When set
to 0, the path cost is set using the 802.1D recommended values.
BPDU Filter
When enabled, this feature filters the BPDU traffic on the edge ports. When spanning tree is
disabled on a port, BPDU filtering allows BPDU packets received on that port to be dropped.
When enabling BPDU Filter, also ensure that the desired interfaces are operating as edge
ports by enabling the Admin Edge Port mode for each of those interfaces.
This feature is disabled by default.
BPDU Flood
When enabled on a port, if the port receives a BPDU packet and STP is disabled on the port,
the BPDU is flooded to all switch ports that are also disabled for spanning tree. This feature
is enabled by default.
Root Guard
When enabled on a port, that port cannot be selected as the root port even if it receives
superior STP BPDUs. The port is assigned an “alternate” port role and enters a blocking state
if it receives superior STP BPDUs. Select this option to enable root guard for the port. This
feature is disabled by default.
Loop Guard
When enabled on a port, this setting prevents the port from erroneously transitioning from the
blocking to the forwarding state when it stops receiving BPDUs. The port is marked as being
in the loop-inconsistent state. In this state, the interface does not forward frames. This feature
is disabled by default.
TCN Guard
When enabled on a port, the port does not propagate received topology change notifications
and topology changes to other ports. This feature is disabled by default.
Port Status and Statistics
Edge Port
Indicates whether the port is currently operating as an Edge port, either due to administrative
configuration or to automatic configuration by the Auto Edge feature.
Point-to-point MAC
Indicates whether the port connects to a single device (True) or to a shared medium with
multiple devices (False). A point-to-point link has only one device at the far end.
Hello Time
The amount of time the port waits between sending “hello” BPDUs.
Bridge Identifier
A unique value that identifies the bridge. It is automatically generated based on the bridge
priority value and the base MAC address of the bridge.
Forward Delay
The amount of time in seconds a bridge remains in the listening and learning state during STP
convergence, before moving to the forwarding state.
Root Path Cost
The path cost to the designated root bridge. Traffic from a connected device to the root bridge
takes the least-cost path to the bridge. If the value is 0, the cost is automatically calculated
based on port speed.
Root Port
The port on the switch with the least-cost path to the designated root bridge in the spanning
tree topology.
Topology Change Count
The number of times the topology of the spanning tree has changed.
Time Since Last Change
The time that has passed since the last spanning tree topology change. This value is reset to
zero when the switch is reset.
Loop Inconsistent State
Identifies whether the interface is currently in a loop-inconsistent state. An interface
transitions to a loop-inconsistent state if loop guard is enabled and the port stops receiving
BPDUs. In this state, the interface does not transmit frames.
Transitions Into Loop
Inconsistent State
The number of times the port has transitioned into loop inconsistent state.
Transitions Out Of Loop
Inconsistent State
The number of times this interface has transitioned out of loop-inconsistent state.
Field
Description
